A man convicted of the 1989 rape and murder of a pregnant woman was executed today in Ohio using a two-drug method never applied before in the United States, the state corrections department said.

Dennis McGuire (53) was pronounced dead at 10.53am at a state prison, the Ohio Department of Rehabilitation and Correction said in a statement.

McGuire received a combination of the sedative midazolam and pain killer hydromorphone, a mix Ohio added as a substitute option in case it had difficulty obtaining pentobarbital, a drug whose manufacturer has objected to its use in executions.

Lawyers for McGuire had argued in a last minute appeal rejected on Monday by a federal judge that the never-before used drug combination would put him at a substantial risk of severe pain and a terrifying inability to obtain breath before he lost consciousness during the execution.

US district judge Gregory Frost had said McGuire failed to demonstrate a substantial risk of severe pain, though he also said that did not mean the court was convinced the execution would be pain-free or even complication-free.

McGuire was convicted of the rape, kidnapping and murder of Joy Stewart, whose body was found by hikers in woods in western Ohio a day after she had been seen talking with McGuire, according to court records.